System and method using low emissions gas turbine cycle with partial air separation

Abstract

A system and method of reducing gas turbine nitric oxide emissions includes a first combustion stage configured to burn air vitiated with diluents to generate first combustion stage products. A second combustion stage is configured to burn the first combustion stage products in combination with enriched oxygen to generate second combustion stage products having a lower level of nitric oxide emissions than that achievable through combustion with vitiated air alone or through combustion staging alone.

Description

BACKGROUND[0001]This invention relates generally to gas turbine power plants, and more particularly, to a system and method for reducing gas turbine nitric oxide (NOx) emissions without incurring penalties associated with either combustion efficiency or carbon monoxide (CO) emissions.[0002]Pollutant emissions from gas turbine power plants have been of great concern in the past several decades. Stringent regulations have been established to lower these emissions, especially nitric oxides to single digits. One of the solutions currently in use to reduce these NOx emissions employs selective catalytic reactors (SCR)s. Selective catalytic reactors undesirably are expensive, have a large footprint, and present additional concerns regarding ammonia slip.[0003]Combustion with vitiated air is a proven technique for reducing NOx emissions by affecting the NOx kinetic mechanisms, changing the flame structure and lowering the peak flame temperature. Combustion staging has also been shown to re...

AI Technical Summary

Benefits of technology

"The patent describes a gas turbine combustion system that reduces nitric oxide emissions through a two-stage combustion process. The system includes a first combustion stage that burns air with diluents to produce first combustion stage products, which are then combined with enriched oxygen in a second stage to produce second combustion stage products with lower nitric oxide emissions levels. This method can help to achieve more efficient and effective reduction of nitric oxide emissions from gas turbines."

Problems solved by technology

One of the solutions currently in use to reduce these NOx emissions employs selective catalytic reactors (SCR)s. Selective catalytic reactors undesirably are expensive, have a large footprint, and present additional concerns regarding ammonia slip.

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